DPFE sensor

Hi guys

All the while this was sticking back in my sub conscious. That DPFE sensor. I'm so glad that some one mentioned it.

I think this could be part of my mis problem as well. I found a fairly decent write up for the Ford Focus. It applys to all of us with the Fords that have the sensor. It was the first thing that came up when I goggled DPFE. Check out, the link below. I'm going to try disconnecting and plugging my vac line going to the egr and see if the miss goes away. If my trouble code changes from random misfire to some sort of egr code. That will tell me something for sure. I'm on this one like a dog on a bone.


http://www.focushacks.com/printable.php?modid=80&ht=DPFE%20Sensor%20and%20EGR%20Information (http://www.focushacks.com/printable.php?modid=80&ht=DPFE%20Sensor%20and%20EGR%20Information)

I terminated my EGR + PCV systems years ago!

Well plugging off the egr vac hose didn't do anything for me. Still has the multiple cyl random misfire code showing up. So much for that idea.

Daniel was that stuff plugged off on a 4.6 engine? I have all that egr and emission stuff eliminated on my old scrap truck. It has a SBC under the hood and doesn't need any of that stuff.

Yep!
Isolating the EGR + PCV systems will help protect the Air filter, MAF, IACT, and O2 sensor from oil blow by.

1) No more unmetered air leaks, because of air leaks on egr + pcv systems.
2) No more contaminated air filters, maf/iact sensors.
3) more horse power!

The high mileage 4.6L with bad valve stem seals will actually have less emissions, and burn less oil.

Like a tic on a dog, I know you will weed out the problem!

This car has been giving me the finger for the last 2 years or so. It's not going to get the best of me, that's for sure.

I had a miss in light throttle cruise related to the EGR/DPFE a few months ago after doing my PI intake swap. One thing that is common with the DPFE sensors is for them to get water condensation in them. Remove the DPFE and tap the water out if you have not done so yet. I also started the car for a few minutes witht he DPFE sensor removed to let any condensation in those two rubber tubes to blow out.

And regarding disabling the EGR system, it does increase horsepower but decreases efficiency, and in some cases may cause a lean condition and cause misfires. The PCM is expecting the air charge to be hotter than what the IAT reads when the EGR is commanded open - therefore a less dense volume of air and it leans the fuel back to compensate. The best way to disable the EGR system is to reflash the PCM with a configuration with the EGR system disabled - then you can remove the hardware and block it off.

If the EGR + PCV system is isolated, do a smoke test for unmetered air leaks,
It could be a bad intake or gasket.

get a scan tool or miltimeter dpfe voltage at idle should be around 1 volt if it is anything more or less then this it is bad or the sensor hoses are bad.

Here's a Redneck smoke test -
1) Remove air filter
2) Wrap plastic wrap around the air filter, for blockage.
3) Put the air filter back in, you dont want smoke coming out of air box during the test.
4) Disconnect the brake booster vacuum hose.
5) Light a Black + mild cigar, and hold smoke.
6) Slowly blow smoke through the brake booster hose and block with thumb.
7) Watch for smoke leaks.

Don't forget to remove the plastic wrap when done with the Redneck smoke test.